A functional OTB template typically includes the following columns or sections:
The actual or estimated stock on hand at the start of the month. Essential Spreadsheet Components
A column for inventory that has already been purchased but has not yet arrived.
3 Reasons Open-to-Buy is THE Critical Planning Tool for Retailers
At its most basic level, your spreadsheet uses this logic to determine your available budget:
A calculation to ensure you aren't over-investing relative to your sales volume. Why Retailers Use OTB Spreadsheets